initial push of array view codes. tests for block views

skimage/util/tests/test_array_views.py

@@ -0,0 +1,67 @@
+import numpy as np
+from nose.tools import raises
+from numpy.testing import assert_equal
+from skimage.util.array_views import block_view
+
+
+@raises(ValueError)
+def test_block_view_block_not_a_tuple():
+
+    A = np.arange(10)
+    block_view(A, [5])
+
+
+@raises(ValueError)
+def test_block_view_negative_shape():
+
+    A = np.arange(10)
+    block_view(A, (-2))
+
+
+@raises(ValueError)
+def test_block_view_block_too_large():
+
+    A = np.arange(10)
+    block_view(A, (11,))
+
+
+@raises(ValueError)
+def test_block_view_wrong_block_dimension():
+
+    A = np.arange(10)
+    block_view(A, (2,2))
+
+
+@raises(ValueError)
+def test_block_view_1D_array_wrong_block_shape():
+
+    A = np.arange(10)
+    block_view(A, (3,))
+
+
+def test_block_view_1D_array():
+
+    A = np.arange(10)
+    B = block_view(A, (5,))
+    assert_equal(B, np.array([[0, 1, 2, 3, 4],
+                              [5, 6, 7, 8, 9]]))
+
+
+def test_block_view_2D_array():
+
+    A = np.arange(4*4).reshape(4,4)
+    B = block_view(A, (2,2))
+    assert_equal(B[0,1], np.array([[2, 3],
+                                   [6, 7]]))
+    assert_equal(B[1, 0, 1, 1], 13)
+
+
+def test_block_view_3D_array():
+
+    A = np.arange(4*4*6).reshape(4,4,6)
+    B = block_view(A, (1,2,2))
+    assert_equal(B.shape, (4, 2, 3, 1, 2, 2))
+    assert_equal(B[2:, 0, 2], np.array([[[[52, 53],
+                                          [58, 59]]],
+                                        [[[76, 77],
+                                          [82, 83]]]]))